1. Field of the Invention
This invention is generally directed to dental instruments and more particularly to dental scalers and curettes wherein the cutting blade portion of the instruments are mounted to the handle of the instruments through an intermediate shank which is primarily of an elongated arcuate configuration which extends from the lower end of the instrument handle to a relatively short and transversely oriented straight segment from which the cutting blade extends. The shank segment is generally oriented at an obtuse angle with respect to the arcuate shank with the cutting blade being oriented at an acute angle with respect to the arcuate shank.
With this type of configuration, the arcuate shank acts as a barrier or spacing element to retain the cheek or tongue in space relationship to the tooth being scaled or curettaged. In another embodiment of the present invention, the upper surface of the cutting blades of the instrument are formed having concave, V-shaped or dished grooves therein which are spaced inwardly from the cutting edges of the blades for purposes of creating troughs or traps in which material scraped from a tooth or a root may be retained as the instrument is raised relative to the tooth. With this type of configuration, the accidental deposit of scraped tartar, debris or other material below the gum line during patient treatment is prevented.
In a further embodiment, the lower surface of the cutting blades of scalers or curettes are tapered downwardly to form a round wedge which will allow the blade to be gently urged between a tooth and the patient's gum.
2. History of the Related Art
Heretofore there have been many developments with regard to improving dental scalers and curettes. In applicant's co-pending patent application entitled Scalers for Periodontal Use, filed concurrently herewith, several types of prior art scaler configurations are discussed in greater detail. In addition, in the co-pending application, there is disclosed a unique configuration for dental instruments of the scaler and curette type which allows for a more efficient scaling of a patient's teeth by orientation of the cutting edges of the blades of such instruments to be compatible with the natural curvature of the tooth along a plane generally normal to the central or elongated axis of the tooth and wherein the curvature is such that an extended line of contact of the cutting edge and the tooth surface will be maintained when the instrument handle is oriented between angles of approximately 45 degrees and 90 degrees with respect to the axis of a tooth. Also, in the co-pending application, several types of cutting edge configurations are disclosed which enable the removal of excessive tartar or other debris or which are useful in treating irregular surface configurations.
Although conventional scalers and curettes provide for various forms of scaling action relative to the surface of a tooth, such structures have generally not adequately provided for the removal of scraped material during scaling and curettaging. Again, in applicant's co-pending application, a modified instrument blade is disclosed wherein the outer tip portion of the blade is vertically curved so as to assist in raising material that is scraped by acting as a spoon-like structure. Unfortunately, although this structure provides for some removal of scraped debris, it is not always efficient in providing maximum entrapment and removal of scraped tartar and other debris.
In addition to the foregoing, in most conventional scalers and curettes, the cutting blade is connected to the handle by an angular or offset shank portion which normally includes first and second diagonally oriented portions. Although such offset orientations of the blade with respect to the instrument handle allows the practitioner to observe the cutting blade more carefully during patient treatment, such structures have not been completely effective in retaining portions of the cheek or tongue from the area being treated thereby resulting in a partial obstruction of the area being treated as well as the possibility of such areas being accidentally injured during treatment.
Some examples of prior art dental scalers and curettes are disclosed in U.S. Pat. Nos. 1,220,933 to Bates, 1,605,320 to Bates, 1,605,321 to Bates, 1,605,322 to Bates, 1,497,749 to Djack, 2,002,245 to McDaniel and 2,366,671 to Montelius.